var gg = function (strs){
    if (strs === null || strs.length ===0)
    {
        return ''
    }
    var str =strs[0]
    for (var i=1; i<strs.length ;i++)
    {
        for (var j=0 ; j<strs.length ; j++)
        {
            if (str.charAT[j] !== strs[i].charAT[j])
            {
                break;
            }
        }
         str =str.substring(0,j)
    }
    return str ;
}

var strs =['addf','addji','addih']
console.log(gg(strs));

var zhanghong = {
    name :'叶陈辉' ,
    age : 20 ,
    birthday :2044010137 
 
}

console.log(yechenhui.name);
yechenhui.school ='软件技术1班'
console.log(yechenhui.school);
delete yechenhui.text
console.log(yechenhui);
console.log('name' in yechenhui)

var height = 1.75;
var weight =80.5;
var height2 =height *height
var bmi =weight / height2

if (bmi <18.5){
    console,log('有点轻啦')
}
else if(bmi>18.5 && bmi<25){
    console.log('还不错');
}
else if(bmi>=25 && bmi<28){
    console.log('有点重啦')
}
else if(bmi>=28 && bmi<32){
    console.log('超重');
}
else if(bmi>=32){
    console.log('严重招标啦')
}